The present invention relates to an antenna device to be mounted on a roof or the like of a vehicle.
Japanese Patent Publication No. 2001-168615A discloses an antenna device in which an antenna base on which a proximal end of an antenna element is disposed is fixed on a vehicle body such as a roof, by inserting a mount screw projected from the antenna base into a mount hole formed in the vehicle body, and screwing a nut to the mount screw via a pawl washer to fasten the antenna base onto the vehicle body. Incidentally, a pawl of the pawl washer bites an inner face of the vehicle body to ground the mount screw to the vehicle body while preventing the nut from being loosened.
In the above structure, the mount screw is provided as a hollow member through which a cable is inserted, so that an antenna signal of the antenna element is input or output via the cable.
Accordingly, in order to mount such an antenna device onto the vehicle body, it is necessary to conduct a fixing operation of the cable in addition to the fastening operation of the mount screw and the nut.